JP2009135335A - Capacitor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and inexpensive electric double-layer capacitor unit capable of achieving high voltage resistance. <P>SOLUTION: Disclosed is the capacitor unit including a plurality of electric double-layer capacitors 1, 2 and 3 and a sealing means of sealing the whole sealing parts of the electric double layer capacitors 1, 2 and 3. The sealing means includes a circuit board 4 and a case 5 having a recessed portion 51 formed in a shape corresponding to the plane shape of the circuit board 4 so that the electric double layer capacitors 1, 2 and 3 are connected on the same plane to be unitized. The electric double layer capacitors 1, 2 and 3 are connected in series so that the sealing parts of the plurality of electric double layer capacitors 1, 2 and 3 are connected to the reverse side of the circuit board 4, and the case 5 has its recessed portion 51 fitted to the circuit board 4 to cover the entire surface of the circuit board 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a capacitor unit for easily increasing the withstand voltage of an electric double layer capacitor. In particular, the present invention serializes a plurality of cylindrically wound electric double-layer capacitors on a circuit board, and a cylindrical resin case with a bottomed shape is fitted from above onto the cylinder so as to be concave with respect to the lower part. It relates to a capacitor unit.

  An electric double layer capacitor is a capacitor based on the principle of operation called “electric double layer”, which stores electric charge on the surface where two different layers of solid and liquid are in contact. It has characteristics such as extremely long life because it is stable against repeated charging and discharging, and no harmful heavy metals are used, and there is no concern about environmental pollution.

  Such an electric double layer capacitor can charge and discharge with a larger capacity than an aluminum electrolytic capacitor. Therefore, it is promising in a wide range of industrial fields such as portable information devices, electric vehicles, various auxiliary power supplies, and late-night power storage.

  However, the withstand voltage of an electric double layer capacitor using an organic electrolyte is generally 2.5 V to 2.7 V, and when used at a voltage higher than that, the electrolytic solution is not electrolyzed. Acceleration causes a decrease in capacitance and an increase in internal resistance, leading to a significant deterioration in electrical characteristics. In addition, the product life is accelerated and shortened, for example, the product expands due to an increase in internal pressure due to the generation of internal gas. Therefore, it is desired to increase the withstand voltage from the structural aspect of the electric double layer capacitor.

  As one means for increasing the withstand voltage, a cell in which a pair of polarizable electrodes are opposed to each other in an electrolyte solution via a separator to form a positive electrode and a negative electrode is formed as a single cell, which is composed of a plurality of anode foils and cathode foils. Are laminated with separators and conductive rubber interposed between them to form a multilayer electric double layer capacitor unit having a series structure, or a plurality of conductive rubber sheets interposed therebetween. An electric double layer capacitor unit or the like in which the capacitor elements are brought into surface contact with each other and connected in series and housed in a metal case can be exemplified (see, for example, Patent Document 1).

JP 2000-208378 A

  However, the following problems have been pointed out in the technique proposed in Patent Document 1 and the like.

  First, since conductive rubber or the like is used at the connection location, the contact resistance is large, and as a result, the equivalent series resistance (ESR) is increased.

  2ndly, since it has several cells in the case, cells are adjoining and it is easy to short-circuit. Therefore, it is necessary to reliably insulate each other's poles. In other words, it is necessary to prevent a plurality of cells from being short-circuited by the electrolytic solution, and it is necessary to consider the amount of impregnation of the electrolytic solution. Therefore, if the amount of the electrolytic solution is reduced in order to prevent short-circuiting between cells, the impregnation of the electrolytic solution becomes insufficient, which causes a decrease in the appearance rate of capacitance or an increase in internal resistance. Moreover, in order to prevent said short circuit, although electrolyte which consists of a solid electrolyte and a gel may be used as electrolyte of electrolyte solution, it will be inevitable that an equivalent series resistance will be caused even if it uses which electrolyte. Furthermore, with this structure, multiple elements are enclosed in the same case, and it is difficult to incorporate a balance circuit that keeps the balance of voltage balance in each cell, so it is necessary to consider overvoltage protection for each cell. Become.

  The present invention has been made in view of the above technical problem, and an object of the present invention is to provide an electric double layer capacitor unit that can increase the voltage easily and at low cost.

  In general, the withstand voltage of a unit capacitor is determined by the electrolysis voltage of an electrolytic solution (electrolyte and its solvent) that is a constituent element, and is about 1.2 V in the case of an aqueous electrolyte, and in the case of an organic electrolyte Is 2.8 to 3.0V. When a voltage higher than the solvent decomposition voltage is applied, the capacitor is destroyed. Therefore, when a high voltage is required depending on the application, a plurality of unit capacitors are connected in series.

  Therefore, in order to achieve the above object, the capacitor unit according to the present invention is a capacitor element in which a separator is interposed between a pair of polarizable electrode materials having pores formed by activating a carbon material. A plurality of electric double layer capacitors having a pair of electrode terminals derived from the polarizable electrode material, and covering the entire sealing portions of the plurality of electric double layer capacitors, A sealing unit for sealing, wherein the sealing unit connects the plurality of electric double layer capacitors on the same plane to form a unit, And a bottomed cylindrical case made of an insulating resin in which a concave portion having a shape corresponding to the planar shape of the circuit board is formed, and the circuit board includes the plurality of electric doubles on one surface thereof. The plurality of electric double layer capacitors are connected in series or in series and parallel so that each sealing portion of the capacitor is in contact, and the recess of the case is fitted to the circuit board so as to cover the entire other surface of the circuit board. Has been.

  In the above configuration, the electric double layer capacitor is unitized by fitting the circuit board and the case. Therefore, the withstand voltage and vibration resistance of the capacitor unit are improved, and the unitization work is simplified.

  In the capacitor unit, a balance resistor is connected in parallel to each electric double layer capacitor connected in series on the circuit board.

  The resistance value of the balance resistor is arbitrary, but is desirably sufficiently larger than the resistance value of the single electric double layer capacitor.

  Further, the capacitor unit has a unit terminal connected to a lead lead drawn from a sealing portion of each electric double layer capacitor on the other surface of the circuit board to which the plurality of electric double layer capacitors are connected in series. The diameter of the unit terminal is set to be larger than the diameter of the lead lead.

  In addition, as a material of the said unit terminal, it is desirable that it is a cheap and highly conductive metal, such as iron and copper.

  According to the present invention, it is possible to provide an electric double layer capacitor unit that has a high withstand voltage, a low equivalent series resistance, is inexpensive because it does not have a complicated work process, and is excellent in vibration resistance and easy to handle. It becomes.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a simplified configuration of a capacitor unit according to an embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a cross-sectional view.

  Referring to FIG. 1, the capacitor unit according to the present embodiment includes three electric double layer capacitors 1, 2, 3 in series on a circuit board 4 to form a unit, and a concave case on the circuit board 4. A high withstand voltage is achieved by fitting 5. In addition, in this capacitor unit, balance resistors 6, 7, 8 are installed in parallel on the electric double layer capacitors 1, 2, 3 connected in series on the circuit board 4.

  Each of the electric double layer capacitors 1, 2 and 3 comprises a polarizable electrode material having pores formed by activating a carbon material, and an electrolyte solution for a capacitor containing an electrolyte and dipping an electrode member. Specifically, each of the electric double layer capacitors 1, 2 and 3 is electrolyzed by decompression or pressurization on an electric double layer capacitor element in which a pair of belt-like positive and negative electrodes are wound in a cylindrical shape through two separators. After the electric double layer capacitor element impregnated with the electrolyte is joined to the sealing material and the sealing material, it is sealed in the aluminum case and sealed with the sealing material, and then covered with the exterior material. Has been.

  In this capacitor unit, the three electric double layer capacitors 1, 2 and 3 are connected on the same plane as a sealing means for covering the entire sealing portions of the three electric double layer capacitors 1, 2 and 3. Therefore, the circuit board 4 and the case 5 are provided.

  In the present embodiment, a circuit board 4 as shown in FIG. 2 is used when three electric double layer capacitors 1, 2, 3 are serialized. 2A and 2B are diagrams showing the configuration of the circuit board, where FIG. 2A is a plan view and FIG. 2B is a cross-sectional view.

  As shown in FIG. 2, the circuit board 4 has a circular planar shape, and is mainly an electrically insulated insulating substrate part 41 and four circuit pattern parts 42, 43, 44 having conductivity. , 45.

  As shown in FIG. 2A, the circuit pattern portions 42, 43, 44, and 45 are fixedly formed on the surface of the circuit board 4 based on a predetermined circuit design.

  The first circuit pattern portion 42 is a common circuit pattern portion shared by the first electric double layer capacitor 1 and the third electric double layer capacitor 2. The second circuit pattern portion 43 is a common circuit pattern portion shared by the second electric double layer capacitor 2 and the third electric double layer capacitor 3. The third circuit pattern portion 44 is a circuit pattern portion dedicated to the first electric double layer capacitor 1. The fourth circuit pattern portion 45 is a circuit pattern portion dedicated to the second electric double layer capacitor 2.

  The first circuit pattern portion 42 and the second circuit pattern portion 43 are arranged to face each other across the center line of the circuit board 4, and the planar shape thereof is a strip shape extending in a straight line along the center line. It is said that. In the first circuit pattern portion 42, a through hole 421 into which the anode lead lead rod 12 of the first electric double layer capacitor 1 is inserted is formed at one end portion, and a third electric pattern is formed at the other end portion. A through hole 422 into which the cathode lead bar 31 of the double layer capacitor 3 is inserted is formed. In the second circuit pattern portion 43, a through hole 431 into which the cathode lead lead bar 21 of the second electric double layer capacitor 2 is inserted is formed at one end portion, and a third electric pattern is formed at the other end portion. A through hole 432 into which the anode lead lead bar 32 of the double layer capacitor 3 is inserted is formed.

  The third circuit pattern portion 44 and the fourth circuit pattern portion 45 are disposed to face each other with the first circuit pattern portion 42 and the second circuit pattern portion 43 interposed therebetween, and the planar shape thereof is an L-shape. Has been. In the third circuit pattern portion 44, a through hole 441 through which the cathode lead lead bar 11 of the first electric double layer capacitor 1 is inserted is formed at one end near the edge of the circuit board 4. The unit terminal 9 is planted at the other end near the circuit pattern portion 42. In the fourth circuit pattern portion 45, a through hole 451 through which the anode lead lead rod 22 of the second electric double layer capacitor 2 is inserted is formed at one end near the edge of the circuit board 4. The unit terminal 10 is planted at the other end portion of the second circuit pattern portion 43.

  Referring to FIG. 1 again, the anode lead lead rod 12 of the first electric double layer capacitor 1 inserted into the through hole 421 of the first circuit pattern portion 42 and the through hole 441 of the third circuit pattern portion 44, and A first balance resistor 6 is connected to the cathode lead lead 11. Between the cathode lead lead bar 21 and the anode lead lead bar 22 of the second electric double layer capacitor 2 inserted through the through hole 431 of the second circuit pattern portion 43 and the through hole 451 of the fourth circuit pattern portion 45. Is connected to the second balance resistor 7. Between the cathode lead lead bar 31 and the anode lead lead bar 32 of the third electric double layer capacitor 3 inserted through the through hole 422 of the first circuit pattern portion 42 and the through hole 432 of the second circuit pattern portion 43. Is connected to a third balance resistor 8. The resistance values of the balance resistors 6, 7, and 8 are arbitrary, but are preferably sufficiently larger than the resistance value of the electric double layer capacitor alone.

  The unit terminals 9 and 10 are connected to each other via the circuit pattern portions 42, 43, 44, and 45 on the surface of the circuit board 4 to which the first to third electric double layer capacitors 1, 2, and 3 are connected in series. Terminals connected to the lead lead rods 11, 12, 21, 22, 31, 32 drawn out from the sealing portions of the electric double layer capacitors 1, 2, 3, and are inexpensive and highly conductive, such as iron and copper It is made from metal. The diameter dimension of the pair of unit terminals 9 and 10 standing upright on the circuit board 4 is set larger than the diameter dimension of the lead lead bars 11, 12, 21, 22, 31 and 32.

  The case 5 is a bottomed cylindrical case made of an insulating resin, and a circular recess 51 having a shape substantially matching the outer shape of the circuit board 4 is formed on the inner surface thereof. Is formed. The recess 51 is fitted to the circuit board 4 so as to cover the entire surface of the circuit board 4. The case 5 has unit terminal insertion holes 52 and 53 through which the unit terminals 9 planted on the circuit board 4 are inserted.

  FIG. 3 shows an arrangement state when three electric double layer capacitors 1, 2, 3 are connected in series on the circuit board 4. The assembly procedure of the capacitor unit will be described mainly with reference to FIG.

  The anode lead lead rod 12 of the first electric double layer capacitor 1 is passed through the through hole 421 of the first circuit pattern portion 42 common to the first electric double layer capacitor 1 and the third electric double layer capacitor 3, and the cathode is drawn out. The lead bar 11 is passed through the through hole 441 of the third circuit pattern portion 44 dedicated to the first electric double layer capacitor 1. The cathode lead lead bar 21 of the second electric double layer capacitor 2 is passed through the through hole 431 of the second circuit pattern portion 43 common to the second electric double layer capacitor 2 and the third electric double layer capacitor 3, and the anode is drawn out. The lead bar 22 is passed through the through hole 451 of the fourth circuit pattern portion 45 dedicated to the second electric double layer capacitor 2. The cathode lead lead bar 31 of the third electric double layer capacitor 3 is passed through the through hole 422 of the first circuit pattern portion 42 common to the first electric double layer capacitor 1 and the third electric double layer capacitor 3, and the anode is drawn out. The lead bar 32 is passed through the through hole 432 of the second circuit pattern portion 43 common to the second electric double layer capacitor 2 and the third electric double layer capacitor 3. Thereafter, the through holes 421, 422, 431, 432, 441, and 451 on the circuit board 4 are fixed by soldering, and the three electric double layer capacitors 1, 2, and 3 have a series structure. At this time, the lead lead bars 11, 12, 21, 22, 31, 32 that protrude from the circuit board 4 are cut off. The three electric double layer capacitors 1, 2, 3 used here are preferably those that are as close as possible in terms of electrical characteristics.

  Next, balance resistors 6, 7, and 8 are installed in parallel to the electric double layer capacitors 1, 2, and 3, respectively.

  Finally, as shown in FIG. 1, the recess 51 of the case 5 is fitted into the circuit board 4 from above the circuit board 4. At this time, the unit terminals 9 and 10 are inserted into the unit terminal insertion holes 52 and 53 of the case 5.

  As described above, in this embodiment, since the electric double layer capacitors 1, 2, and 3 are unitized by fitting both the circuit board 4 and the case 5, the withstand voltage and vibration resistance of the capacitor unit are improved. In addition to improving, unitization work is simplified.

  In particular, the diameter dimensions of the unit terminals 9 and 10 planted on the circuit board 4 are larger than the diameter dimensions of the lead lead bars 11, 12, 21, 22, 31 and 32 of the electric double layer capacitors 1, 2 and 3. Since the size is increased, it is possible to provide a capacitor unit having excellent vibration resistance without impairing the characteristics of low resistance when performing surface mounting.

  Examples of the present invention are shown below. About the unit which connected three electric double layer capacitors mentioned above in series, charging / discharging was performed 5 times by the charging / discharging electric current of 140 mA with the voltage of 5.5V, and the average value of the electrical property was computed. In addition, as a comparative example, characteristics were confirmed using a multilayer electric double layer capacitor of the same size. In addition, the member used was produced using what is used universally for both the Example and the comparative example. The results are shown in Table 1.

  As is apparent from Table 1, it can be seen that the electric double layer capacitor unit according to the example has a smaller equivalent series resistance than the multilayer electric double layer capacitor of the comparative example.

  In the above embodiment, the electrostatic capacity and the equivalent series resistance are compared, but the self-discharge characteristics that are particularly important in the memory backup application are also compared. Table 2 shows the results of measuring the voltage across the capacitor terminals after charging for 8 hours at 5.5V.

  As can be seen from Table 2, in the example having self-discharge characteristics, a result that a higher voltage was maintained for a longer time than that of the multilayer electric double layer capacitor was obtained. It was confirmed that superiority was seen.

  As can be seen from the above comparison results, according to the present invention, an electric double layer capacitor unit having a lower equivalent series resistance than the multilayer electric double layer capacitor and having good self-discharge characteristics can be realized. In addition, unlike a multilayer electric double layer capacitor, it is not housed in the same case, so a balance circuit can be installed arbitrarily, so that it is possible to maintain a balanced voltage balance between products. Stable reliability can also be expected. Furthermore, by providing a unit terminal larger than the diameter of the lead-out lead bar of each capacitor on the circuit board in which each electric double layer capacitor is connected in series, when performing surface mounting, without impairing the characteristics of low resistance, It was confirmed that a capacitor unit with excellent vibration resistance can be provided.

  In addition, this invention is not limited to the said embodiment (Example). For example, in the above-described embodiment (example), a plurality of cylindrical electric double layer capacitors are connected in series on one surface of the circuit board. The same effect can be obtained by connecting a plurality of elliptical capacitors in series or in series-parallel. It goes without saying that various design changes and modifications can be made within the scope of the claims attached to this specification.

  The present invention is useful as an electric double layer capacitor unit because it can increase the voltage easily and at low cost.

It is a figure which simplifies and shows the structure of the capacitor | condenser unit which concerns on embodiment of this invention, Comprising: (A) is a top view, (B) is sectional drawing. It is a figure which shows the structure of a circuit board, Comprising: (A) is a top view, (B) is sectional drawing. It is a figure which shows the arrangement | positioning state at the time of connecting a some electrical double layer capacitor in series on a circuit board, Comprising: (A) is a top view, (B) is sectional drawing.

Explanation of symbols

1, 2, 3 Electric double layer capacitors 11, 12, 21, 22, 31, 32 Drawer lead bar 4 Circuit board 5 Case 51 Recess 6, 7, 8 Balance resistor 9, 10 Unit terminal

Claims (3)

A capacitor element wound with a separator interposed between a pair of polarizable electrode materials having pores formed by activating a carbon material is impregnated in an electrolytic solution and accommodated in a case, and the polarizable electrode material A capacitor unit comprising: a plurality of electric double layer capacitors having a pair of electrode terminals derived from; and sealing means for covering and sealing the entire sealing portions of the plurality of electric double layer capacitors. There,
The sealing means is
In order to connect the plurality of electric double layer capacitors on the same plane to form a unit, a bottomed cylindrical shape made of an insulating resin having a circuit board and a recess having a shape corresponding to the planar shape of the circuit board Including case,
In the circuit board, the plurality of electric double layer capacitors are connected in series or in series and parallel so that the sealing portions of the plurality of electric double layer capacitors are in contact with one surface thereof,
The above case
A capacitor unit, wherein the recess is fitted to the circuit board so as to cover the entire other surface of the circuit board.   2. The capacitor unit according to claim 1, wherein a balance resistor is connected in parallel to each electric double layer capacitor connected in series on the circuit board. On the other surface of the circuit board to which the plurality of electric double layer capacitors are connected in series, a unit terminal connected to the lead lead drawn from the sealing portion of each electric double layer capacitor is planted,
3. The capacitor unit according to claim 1, wherein a diameter dimension of the unit terminal is set larger than a diameter dimension of the lead lead.

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